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Topic: rear end? Why not just gear and pinions? (Read 5089 times) previous topic - next topic

rear end? Why not just gear and pinions?

Maybe I'm not educated enough to say this,  but by CJ 05 I'd like to have the 3.73 gears in the cougar. But the more i research the more confused I get.

what I'm stuck on is...

Why not just purchase new gear ring and pinion sets for the 7.5 rather then buying a whole rearend out of a donor car.

Gear ring and pinion 159.99
or
$??? from a junkyard. (my junkyard is super expensive for anything)

I'd imagine it'd be a hell of a lot easier switching out the gears (although I dont have any idea how to even start), rather then tearing the whole rearend out, then replacing it with the new 3.73s.

Maybe i just dont know what I'm talking about. Maybe its cheaper over another route.

Any ideas or can anyone set me in the right direction of thinking?

btw

I have a pretty much stock 5.0l
w/ just headers, no cats, h pipe. and an intake.
thats pretty much the only mods done to it.

I've heard many of times to get the quicker acceleration then get the 3.73s. I wont ever really hit the 100mph for the top speed. So 3.73s seems to be the way to go.

Any suggestions and ideas would be awesome.

Re: rear end? Why not just gear and pinions?

Reply #1 –
People swap rears to get the stronger 8.8" rear instead of putting money in to the 7.5". If you plan on putting down any power in the future a 7.5" is virtually useless.
1980 birds X 3, 1982 bird, 1984 XR7, 1988 TC
 

Re: rear end? Why not just gear and pinions?

Reply #2 –
yeah dude, people grab the turbo coupe rears, because they have traction lock, they already have the desired gears (3.73 or 3.55), quad shocks, and disk brakes, on the stronger 8.8 rear

this is where its tricky, putting gears in a rear is not simple by any means, 95% of the time, i say take it to a shop, very precision work, and if youre going to get gears, its best to put a traction lock in, because theres no use of doing gears, and not being able to put it to the ground

doing a rear swap isnt really all that hard, untill you gotta plumb the brake lines
It's Gumby's fault.

Re: rear end? Why not just gear and pinions?

Reply #3 –
ya, sounds like a garage job....
ok so the gear and pinion is out... never tought about those situations.

Ok,
for those of you that went with the 3.73 gears, how much did it cost you to do everything? What est. cost should I be looking at?

Re: rear end? Why not just gear and pinions?

Reply #4 –
Quote
People swap rears to get the stronger 8.8" rear instead of putting money in to the 7.5". If you plan on putting down any power in the future a 7.5" is virtually useless.


Only rear end part I've ever broken on my 7.5 is the left side axle shaft (which is the same exact part as on the 8.8 ear).  I got about 240 HP at the tires (around 290 Flywheel).  They'll take some abuse.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Re: rear end? Why not just gear and pinions?

Reply #5 –
Unless you're doing clutch drops on slicks, the 7.5's will be good for most folks.  You can get Trac-Loc units for the 7.5's and some of the earlier(83-84) TC rears had Auburn differentials instead of the Trac-Loc, which are much nicer IMO.  The 7.5 is also quite a bit lighter too.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Re: rear end? Why not just gear and pinions?

Reply #6 –
Quote from: Chuck W
Unless you're doing clutch drops on slicks, the 7.5's will be good for most folks.  You can get Trac-Loc units for the 7.5's and some of the earlier(83-84) TC rears had Auburn differentials instead of the Trac-Loc, which are much nicer IMO.  The 7.5 is also quite a bit lighter too.


You wouldn't happen to know their weights would you? :D
2005 Subaru WRX STi|daily driver

Re: rear end? Why not just gear and pinions?

Reply #7 –
Not off-hand, but IIRC it is in the neighborhood of 75# difference between the two.  It could be less though.....
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Re: rear end? Why not just gear and pinions?

Reply #8 –
Quote from: Tbird232ci
yeah dude, people grab the turbo coupe rears, because they have traction lock, they already have the desired gears (3.73 or 3.55), quad shocks, and disk brakes, on the stronger 8.8 rear

this is where its tricky, putting gears in a rear is not simple by any means, 95% of the time, i say take it to a shop, very precision work, and if youre going to get gears, its best to put a traction lock in, because theres no use of doing gears, and not being able to put it to the ground

doing a rear swap isnt really all that hard, untill you gotta plumb the brake lines


Yeah, I snagged a TC 8.8" for $150 at tht bone yard - was one of my better purchases.
11.96 @ 118 MPH old 306 KB; 428W coming soon.

Re: rear end? Why not just gear and pinions?

Reply #10 –
There you have it.. :p
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Re: rear end? Why not just gear and pinions?

Reply #11 –
I don't buy that. It's definitely more than 30 lbs. I can pick up a 7.5" by myself all day...the 8.8" is a hell of a lot heavier, and I never move one without help from either a person or a floor jack. I'm thinking a 7.5" with a locking center weighs more than the typical open 7.5" we pull out of these cars. That would explain some of it. But 10 lbs., my ass. That is not right.

Re: rear end? Why not just gear and pinions?

Reply #12 –
Quote from: EricCoolCats
I don't buy that. It's definitely more than 30 lbs.

Do you have any quantitative rather than qualitative data?

The largest weight difference seen was 45 lbs. That was comparing a complete Fox 7.5 to a SN95 8.8. It certainly isn't 80lbs.

Re: rear end? Why not just gear and pinions?

Reply #13 –
Quote from: EricCoolCats
That would explain some of it. But 10 lbs., my ass. That is not right.


you  know your right.. your ass can't  only weigh 10 lbs.. :raspberry ;)

just bustin your ball$ Eric or in this case ass..


on another note an 8.8 is much heavier and stronger then a 7.5..

some people may not agree.. but if i would have stuck with the 7.5 i'm sure i would have changed about 40 of them out by now in my cougar..

i've seen them blow up.. hell i destroyed my old 8.8 with 28spline axles.. anyway if your a person with a car like ours that is stock "155 HP" and you never even plan to do anything even a bernout.. it should last.. but if you plan to tool around and have a little fun and have more then lest say a bone stock motor... it will blow up!!! it may not happen today,next week,next month,or even next year!! but it will blow up one day alot sooner then an 8.8....i've seen both cases where it lasted a long time.. and the cases where someone whom transplants a more then mild motor over 200HP says "ahh screw it!! it will be fine till i get the chance to change the rear.. and goes ripping down the block and BOOM!! and get the car pushed back to the shop or backyard to change the rearend..

oh and yes by the way when i typed the word "backyard" in my mind i said it that way!! not backyad!!! and i'm still not ALLSET!! :crazy:

have a nice day eveyone


Nick
Quote
there's only about a half a dozen man made objects that are herd by the human ear below 40Hz,a pipe organ,thunder,the space shuttle lifting off,a jet airplane taking off or landing,a large canon,an atomic bomb ignited in your back yard and the heat wave afterward oh wait you would be dead so you would'nt hear it scratch that!,and maybe beating your hear against a wall less then 40 times a second..rap music is'nt one of them!thats 40-60Hz@100+db the moving air is under 40Hz

Re: rear end? Why not just gear and pinions?

Reply #14 –
When I rolled the stock 7.5" open 2.73 rear end out of the convertible, I picked it up myself off the jack without too much effort and kindly deposited it beside the garage. This is complete with drum brakes still attached, nothing else removed. The same afternoon I tried to lift the 8.8" TC rear onto the jack myself and nearly herniated myself. That's when I got help from a friend, with another as a backup to work the jack. The TC rear did not have anything removed from it (i.e. mooseballs) and I believe we left the brake hardware attached loosely. I know what I can lift, and what 20 lbs. feels like, and there was way more than 20 lbs. difference between the two relatively stock rear ends. When two people struggle to get one rear end in, while one person can handle the other easily by himself, that's telling you something. In fact, all 3 of us took turns trying to lift each rear end by himself, and we were all shocked at the weight difference of the 8.8". I don't carry a scale in my garage or we would have weighed them both. Is it 40 lbs.? I can maybe see that, although it felt like more. Right now I have a large plastic container filled with TC rear brake parts and can confirm that the rear rotors, calipers, brackets and rubber brake lines together weight more than a complete 11" front brake conversion, spindles and all (I have those in an identical bin next to the rear parts). Again, I don't have access to a large scale to weigh them...but I struggle picking up the bin with the rear components while having a slightly better time with the front parts bin. The rear discs weigh a LOT more than people think. That may be the weight difference right there, I don't know. It would explain a lot.

BTW, the old Visteon link isn't working. Any chance you still have the PDF?